<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>尺寸问题</title>
		<style>
			div#d1{
				width: 50%;
				height: 500px;
				background: rgba(243, 35, 134, .1);
			}
		</style>
	</head>
	<body>
		<div id="d1"></div>
		<div id="container">
			<div class="box">Lorem ipsum dolor sit, amet consectetur adipisicing elit. Voluptatem, dignissimos sed illo quis ut obcaecati assumenda labore aliquid, consectetur cum dolores nemo placeat unde sint! Magnam amet totam quos dicta.</div>
		</div>
	</body>
</html>